UPPER LIP OF MANATEE
may get still more numerous
This large number of grinding
teeth is obviously suggestive o1
the Whales, with which th«
Sirenia are believed by some tc
be allied. It is at least a re-
markable coincidence that thes*
two aquatic groups of mammal*
should both have assumed the
same indefinite tooth formula
It is correct to say assumed,, sinc€
extinct forms of Manatees, sue!
as HalitJierium and Prorastoma
have not a continuous successior
of molars. The brain of the
Manatee is, contrary to the
usual arrangement among aqua-
tic mammals, smooth, and onlj
marked by one or two fissures.
The Manatee * is black iu
colour, its thick skin being
wrinkled. The animal is assisted
in feeding by a curious mechan-
ism of the upper lip ; this is split
in two, and the two halves, which
are furnished with strong bristles,
can play upon each other like
the points of a pair of forceps.
The flippers are furnished with
nails, save in M. inunguis, but in
the nailed forms it is not every
finger which is thus armed.
Hdlieore^ the Dugong, is an
entirely Oriental and Australian
1 Beddard, " Notes upon thts Anatomy
of a Manatee (Maaiatus inunguis},"Proc.
Zool. S&c* 1897, p. 47,
2 See Kiikentha-l in Semon's ** Zoolog,
Forschuiigen," Dentesvhr. Jen.
J^angkavel, «' Eter Dugong," Zwl.
1896, p. 337.